This invention relates to drain cleaners.
Granular household drain cleaners currently available on the market typically include sodium hydroxide, sodium nitrate and aluminum, the sodium hydroxide being the predominant component of the mixture. The sodium hydroxide generates substantial heat as it dissolves in water, thereby melting clogging grease. The sodium nitrate, sodium hydroxide and aluminum react with water to produce ammonia. The gases generated agitate, at least somewhat, the sodium hydroxide so that it is dispersed throughout the water and does not clump. The ammonia then substantially dissolves in the water. The agitation also exposes the clog to fresh sodium hydroxide. If the clog is grease based, the heat of solution of the sodium hydroxide will melt the grease, and some of the grease will be saponified to a soluble soap-like substance.
However, the common household granular drain cleaner is not effective for removing clog aggravating hair which catches on the strainer or on mechanical parts of the stopper mechanism located at or near the top of the drain entry. Hair tends to catch on and hang down from such components and restrict the flow of draining fluid sufficiently that clog formation in the trap is encouraged. While the heat of dissolution of sodium hydroxide will dissolve hair actually located in the trap, hair hanging down from the strainer is too far above the trap to be affected by sodium hydroxide dissolving in the trap below. Frequently a large portion of the hair is located above the water retained in the trap and is not affected by the drain cleaner. The heat of dissolution tends to stay concentrated at the bottom of the trap. While some heat, of course, rises, it is typically not sufficient to dissolve hair hanging from the strainer.
Adding a hypochlorite generator to the granular drain cleaner would be effective in oxidizing such strainer suspended hair. However, hypochlorite generators are typically unstable with the sodium hydroxide in granular form because the two readily react. They cannot be stored for any length of time with each other. In addition, the ammonia, produced in the sodium nitrate reaction with aluminum in sodium hydroxide, will react with the hypochlorite to generate chloramines which can be dangerous. The chloramines at least have an unpleasant odor, and a potential for toxicity. Also it is a possibility, albeit remote, that the explosive trichloramine will form.
Liquid drain cleaners do contain 5 to 6% hypochlorite. The hypochlorite can coexist with the caustic without deterioration because the caustic is present in such dilute form, i.e., 6 to 8%. The significant drawback to liquid drain cleaners however, is that little or no heat is generated when they are added to the water in the drain. The sodium hydroxide is already dissolved and hence, the substantial heat of dissolution of the sodium hydroxide is not created in the clogged drain. This renders liquid drain cleaners much less effective than granular drain cleaners on most clogs.